some advice needed guys my wee diesel pick up is letting the diesel travel back from the pump and if i prime the diesel up its leaking from underneath the diesel pump when driving it revs up and down itself and sometimes just cuts out i have to pump the diesel up everytime i want to start it so any ideas!

if it's leaking at the pump i suspect one of the fuel union banjo bolts is loose in the first instance, failing that the pump is probably shot